Grain Harvesting Fire Safety – WA Wheatbelt FBI/GFBI ≈40 self‑check

A practical, WA‑adapted version of the NSW RFS Grain Harvesting Guide. Measure temperature, humidity and the 10‑minute average wind in‑paddock, look up the FBI≈40 table, and decide whether to pause or continue.

This page links to official DFES/AFDRS resources and explains how to use the guide as best‑practice alongside WA’s legal framework (Total Fire Bans and local Harvest & Vehicle Movement Bans).

How the FBI/GFBI ≈40 method works

  1. Measure local temperature, relative humidity, and the 10‑minute average wind speed in the paddock.
  2. Look up the table for FBI≈40 (from the NSW RFS Grain Harvesting Guide) using your temperature and humidity to find the maximum recommended wind speed.
  3. Decide: if your measured 10‑min average wind is equal to or greater than the table value, do not harvest. Reassess later when conditions ease.

This aligns with Australia’s AFDRS shift and is widely used in NSW; we promote it in WA as a voluntary best‑practice trigger for safer decisions during Wheatbelt harvest.

Tip: Round humidity readings down and average the wind over 10 minutes before comparing to the table.

At‑a‑glance thresholds

Example table cell from the NSW RFS guide:

  • 40 °C & 15% RH ⇒ 21 km/h (10‑min avg).
  • If your 10‑min average wind is ≥ 21 km/h at those temp/RH conditions, pause harvesting and reassess later.

Always use the full table for your actual temperature & humidity pairing.

Worked example

You measure in‑paddock at 2:15 pm: Temp 37 °C, RH 18%, 10‑min avg wind 24 km/h.

Looking up the FBI≈40 table (NSW RFS factsheet), you find the maximum recommended wind for 37 °C/18% RH is around low‑20s km/h. Because your measured average wind (~24 km/h) meets/exceeds that value, you self‑suspend, check again later, and prepare the paddock for response if needed.

Note: use your own table look‑up against the official factsheet rather than relying on this illustrative text.

Daily checks (WA)

  • DFES Total Fire Ban (TFB): look up current TFB status and read what’s allowed vs not allowed.
  • Harvest & Vehicle Movement Ban (H&VMB): these are issued by your local government; DFES shares the info but doesn’t impose them. Always check your Shire’s channels/SMS lists.
  • AFDRS (national Fire Danger Ratings): Moderate / High / Extreme / Catastrophic action guidance.

Links for today

Minimum gear & header hygiene

  • Carry a knapsack (≈16 L) and a portable extinguisher (≥9 L liquid or ≥0.9 kg dry powder) on harvesting plant/vehicles.
  • Water cart/ute‑mounted unit nearby; radio/phone comms; static mitigation (chains), and hot‑surface checks (exhausts/bearings).
  • Keep header dust free (blow‑down schedule), remove accumulations, and maintain firebreaks/access for rapid response.

These are universal good‑practice controls drawn from the NSW guide and common Australian farm‑fire advice.

How this guide fits WA law

This page is best‑practice decision support. In WA, Total Fire Bans are set by DFES, while Harvest & Vehicle Movement Bans are issued by your local government. If a H&VMB is in force, don’t harvest, regardless of your FBI table result.